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Subject[PATCH] media: pci: ttpci: av7110: avoid compiler optimization of reading data[0] in debiirq()
Date
In debiirq(), data_0 stores the value of data[0], but it can be dropped
by compiler optimization. Thus, data[0] is read through READ_ONCE().

Fixes: 6499a0db9b0f ("media: pci: ttpci: av7110: fix possible buffer overflow caused by bad DMA value in debiirq()")
Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jia-Ju Bai <baijiaju@tsinghua.edu.cn>
---
drivers/media/pci/ttpci/av7110.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/pci/ttpci/av7110.c b/drivers/media/pci/ttpci/av7110.c
index bf36b1e22b63..f7d098d5b198 100644
--- a/drivers/media/pci/ttpci/av7110.c
+++ b/drivers/media/pci/ttpci/av7110.c
@@ -406,7 +406,7 @@ static void debiirq(unsigned long cookie)
case DATA_CI_GET:
{
u8 *data = av7110->debi_virt;
- u8 data_0 = data[0];
+ u8 data_0 = READ_ONCE(data[0]);

if (data_0 < 2 && data[2] == 0xff) {
int flags = 0;
--
2.17.1
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